1. Field of the Invention
The present invention relates to a method of controlling a digital photographing apparatus (e.g., a digital camera), and more particularly, to a method of controlling a digital photographing apparatus that receives an image having a resolution with a first pixel number and displays a display image on a displaying unit having a resolution with a second pixel number.
The method of controlling the digital photographing apparatus of the present invention can be adopted in any digital photographing apparatus that captures and stores images in addition to digital cameras. In the present application, a digital camera is used as a typical example in which the present invention can be adopted.
2. Description of the Related Art
FIG. 1 is a front perspective view of a conventional digital camera 1. Referring to FIG. 1, the digital camera 1 includes on its front surface, a microphone MIC, a self-timer lamp 11, a flash 12, a shutter button 13, a mode dial 14, a function-select button 15, a photograph information display unit 16, a view finder 17a, a function-block button 18, a flash-light amount sensor (FS) 19, a lens unit 20, and an external interface unit 21.
When in a self-timer mode, the self-timer lamp 11 operates when the shutter button 13 is pressed until a shutter (not shown) operates. The mode dial 14 is used to select one of various operating modes, for example, a still image photographing mode, a night scene photographing mode, a moving picture photographing mode, a reproducing mode, a computer connecting mode, and a system setting mode. The function-select button 15 is used to select one of the operating modes, for example, a still image photographing mode, a night scene photographing mode, a moving picture photographing mode, or a reproducing mode. The photograph information displaying unit 16 displays various information regarding each function related to photographing. The function-block button 18 is used to select one of the functions displayed on the photograph information display unit 16.
FIG. 2 is a rear view of the digital camera 1 of FIG. 1. Referring to FIG. 2, a speaker SP, a power button 31, a monitor button 32, an automatic focus lamp 33, a view finder 17b, a flash standby lamp 34, a color liquid crystal display (LCD) panel 35, a confirm/delete button 36, an enter/play button 37, a menu button 38, a wide-angle zoom button 39w, a telephoto zoom button 39t, an up-movement button 40up, a right-movement button 40ri, a down-movement button 40do, and a left-movement button 40le are included on the back of the digital camera 1.
The monitor button 32 is used to control the operation of the color LCD panel 35. For example, if the user presses the monitor button 32 a first time, an image of a subject and photographing information is displayed on the color LCD panel 35; when the monitor button 32 is pressed a second time, only the image of the subject is displayed on the color LCD panel 35; and when the monitor button 32 is pressed a third time, power supplied to the color LCD panel 35 is blocked. The automatic focus lamp 33 operates when an automatic focusing operation is completed. The flash standby lamp 34 operates when the flash 12 (see FIG. 1) is on standby. The confirm/delete button 36 is used as a confirm or delete button in the process in which a user sets one of the modes. The enter/play button 37 is used to input data or perform various functions such as stop or play in the reproducing mode. The menu button 38 is used to display a menu of a mode selected from the mode dial 14. The up-movement button 40up, the right-movement button 40ri, the down-movement button 40do, and the left-movement button 40le are used in the process in which a user selects one of the modes.
FIG. 3 is a view illustrating a structure of a surface of the digital camera 1 of FIG. 1 on which light is incident. FIG. 4 is a block diagram of the digital camera 1 of FIG. 1.
An optical system OPS including the lens unit 20 and a filter unit 41 optically processes light reflected from a subject. The lens unit 20 of the optical system OPS includes a zoom lens ZL, a focus lens FL, and a compensation lens CL.
If a user presses the wide-angle zoom button 39w (see FIG. 2) or the telephoto zoom button 39t (see FIG. 2) included in a user inputting unit INP, a signal corresponding to the wide-angle zoom button 39w or the telephoto zoom button 39t is input to a micro-controller 512. Accordingly, as the micro-controller 512 controls a lens driving unit 510, a zoom motor MZ operates, thereby moving the zoom lens ZL. That is, if the wide-angle zoom button 39w is pressed, the focal length of the zoom lens ZL is shortened, and thus increases a viewing angle. On the other hand, if the telephoto zoom button 39t is pressed, the focal length of the zoom lens ZL is lengthened, and thus decreases a viewing angle. According to the above-mentioned characteristics, the micro-controller 512 can calculate a viewing angle based on the location of the zoom lens ZL from design data of the optical system OPS. Since the location of the focus lens FL is altered while the location of the zoom lens ZL is fixed, the viewing angle is hardly affected by the location of the focus lens FL.
When the focus on a subject is automatically or manually fixed, the current location of the focus lens FL changes with respect to a distance Dc to a subject. Since the location of the focus lens FL is changed when the location of the zoom lens ZL is fixed, the distance Dc to the subject is affected by the location of the zoom lens ZL. In the automatic focusing mode, the micro-controller 512 controls the lens driving unit 510, thereby driving a focus motor MF. Accordingly, the focus lens FL moves from the very front to the very back. In this process, a number of steps of the location of the focus lens FL (e.g., a number of location steps of the focus motor MF) are set at which an amount of high frequency in an image signal is increased the most.
The compensation lens CL is not separately operated since it acts to compensate for the overall refractive index.
A motor MA drives an aperture (not shown). A rotation angle of the aperture driving motor MA depends on whether the digital camera 1 is in a specified area exposure mode or in another mode. In the specified exposure mode, when a part of a subject region desired by a user coincides with a specified detected region displayed on the color LCD panel 35 of the digital camera 1, a light amount of the digital camera 1 is set to a mean brightness value of the specified detected region.
An optical low pass filter (OLPF) included in the filter unit 41 of the optical system OPS removes optical noise with a high frequency. An infrared cut filter (IRF) included in the filter unit 41 blocks infrared components of incident light.
A photoelectric converter OEC of a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) (not shown) converts light from the optical system OPS into an electrical analog signal. Here, a digital signal processor (DSP) 507 controls a timing circuit 502 and controls the operation of the photoelectric converter OEC and a correlation double sampler and analog-to-digital converter (CDS-ADC) device 501. The CDS-ADC device 501, which is an ADC, processes the analog signal output from the photoelectric converter OEC, and converts it into a digital signal after removing high frequency noise from the analog signal and altering the bandwidth of the analog signal. The DSP 507 processes the digital signal from the CDS-ADC device 501, and generates a digital image signal divided into a chrominance signal and a luminance signal.
A light emitting unit LAMP that is operated by the micro-controller 512 includes the self-timer lamp 11, the automatic focus lamp 33 (see FIG. 2), and the flash standby lamp 34 (see FIG. 2). The user inputting unit INP includes the shutter button 13 (see FIG. 1), the mode dial 14 (see FIG. 1), the function-select button 15 (see FIG. 1), the function-block button 18 (see FIG. 1), the monitor button 32 (see FIG. 2), the confirm/delete button 36 (see FIG. 2), the enter/play button 37 (see FIG. 2), the menu button 38 (see FIG. 2), the wide-angle zoom button 39w (see FIG. 2), the telephoto zoom button 39t, the up-movement button 40up (see FIG. 2), the right-movement button 40ri (see FIG. 2), the down-movement button 40do (see FIG. 2), and the left-movement button 40le (see FIG. 2).
The digital image signal output from the DSP 507 is temporarily stored in a dynamic random access memory (DRAM) 504. Algorithms needed for the operation of the DSP 507 and for setting data are stored in an electrically erasable and programmable read-only memory (EEPROM) 505. A memory card is inserted into a memory card interface (MCI) 506.
The digital image signal output from the DSP 507 is input to an LCD driving unit 514. As a result, an image is displayed on the color LCD panel 35.
The digital image signal output from the DSP 507 can be transmitted in a series communication via a universal serial bus (USB) connector 21a or an RS232C interface 508 and its connector 21b, or can be transmitted as a video signal via a video filter 509 and a video outputting unit 21c. 
An audio processor 513 outputs an audio signal from the microphone MIC to the DSP 507 or the speaker SP, and outputs an audio signal from the DSP 507 to the speaker SP.
The micro-controller 512 controls the operation of a flash controller 511 according to a signal output from the FS 19, and thus operates the flash 12.
FIG. 5 is a flowchart illustrating a method of controlling photographing of the micro-controller 512 illustrated in FIG. 4.
Referring to FIGS. 1 through 5, the shutter button 13 included in the user inputting unit INP has a two-step structure. That is, if a user presses the shutter button 13 to a first step after the user operates the wide-angle zoom button 39w or the telephoto zoom button 39t, a first signal S1 output from the shutter button 13 is activated, and if the shutter release button 13 is pressed to a second step, a second signal S2 output from the shutter button 13 is activated. Therefore, the algorithm for controlling photographing illustrated in FIG. 5 starts when the shutter release button 13 is pressed up to the first step (Operation 101). Here, the current location of the zoom lens ZL is already set.
Remaining storage space of the memory card is detected (Operation 102), and it is determined whether the storage space is sufficient to record a digital image (Operation 103). If there is not enough storage space, a message indicating a lack of storage space in the memory card is displayed (Operation 104). If there is enough storage space, the following operations are performed.
Automatic white balance (AWB) is performed, and parameters related to the AWB process are set (Operation 105). Then, automatic exposure (AE) is performed in which a brightness of incident light is calculated, and the aperture driving motor MA is operated according to the calculated brightness amount (Operation 106). Then, automatic focusing is performed, and the location of the focus lens FL is set (Operation 107).
Then, it is determined whether a first signal S1, which is a signal generated when the shutter button 13 is at a first step, is activated (Operation 108). If the first signal S1 is inactivated, the user has no intention of photographing, and thus, a perform-program is terminated. If the first signal S1 is activated, the following operations are performed.
First, it is determined whether the second signal S2 is activated (Operation 109). If the second signal S2 is not activated, the user has not pressed the shutter button 13 to the second step for photographing, and thus the method moves to operation 106.
If the second signal S2 is activated, a photographing operation is performed since the user has pressed the shutter button 13 to the second step for photographing. That is, the micro-controller 512 operates the DSP 507, and the timing circuit 502 operates the photoelectric converter OEC and the CDS-ADS 501. Then, image data is compressed (Operation 111), and a compressed image file is generated (Operation 112). After the generated image file is stored in the memory card via the MCI 506 from the DSP 507 (Operation 113), the method is completed.
For reference, Japanese Patent Publication No. hei 11-196301, titled “Electronic Camera Device,” discloses an electronic camera device in which the state of an image, for example, a focusing or a shaking of the image at the moment of photographing, can be easily checked.
FIGS. 6A, 6B, 6B′, and 6C are views illustrating a conventional method of controlling a digital photographing apparatus to enlarge an image to check a focus of the image.
Referring to FIGS. 6A, 6B, 6B′, and 6C, in the conventional method of controlling the digital photographing apparatus, a predetermined region of an image displayed on an image displaying device 35 is set as a focus zone before photographing the image. After displaying an enlarged focus zone, a user focuses the image or presses a shutter switch to perform photographing.
To do so, first, a focus frame 61 for checking the focus of the image is displayed inside a monitor image 60 of the subject, which is displayed on the image displaying device 35, in a recording mode (FIG. 6A). Then, a portion of the image inside the focus frame 61 is automatically or manually at a command of the user enlarged, and displayed on the entire screen 62 or on a portion 63 of the screen (FIGS. 6B and 6B′). Then, the user checks whether the image is in focus by looking at the enlarged image, changes the focus if necessary, and performs photographing, and thus a photographed image 64 is displayed (FIG. 6C).
Image sensors used in digital photographing apparatuses have an increasing number of pixels due to advancements in technology, and the size of an LCD display window, which is an image displaying device, is becoming smaller due to the miniaturization of digital photographing apparatuses. Therefore, there is a large difference between the resolutions of the image sensor and the LCD display window, which is the image displaying device.
However, in the conventional method of controlling the digital photographing apparatus, the focus region is simply enlarged and displayed and resolutions of an image sensor and the image displaying device are not considered. Thus, it is difficult to achieve a good effect in the situation in which there is a large difference between the resolutions of the image sensor and the LCD display window as the image displaying device.